Women have been urged to keep active during their pregnancy.
Jo Taylor, midwife for the baby charity Tommy's, stated that women who make an effort to remain relatively fit during pregnancy will receive a number of health benefits.
Those who exercise are more likely to help control weight gain during pregnancy and will also reduce the stresses on the body during labour.
"Pregnant women, however, should avoid contact, high-impact sports - walking and swimming are good exercises for pregnancy," she added.
Ms Taylor recommended that women who did not exercise prior to becoming pregnant should begin their programme by participating in 15 minutes of continuous physical activity on three separate occasions each week before they can progress to daily exercise.
Her comments came after a study published in the Acta Obstetricia et Gynecologica Scandinavia found that a mother's pre-pregnancy weight and weight gained during the term have an impact on the birthweight of their children.